Floating type drive spike accessory

ABSTRACT

A tool or accessory for use in conjunction with paving breakers or similar power hammers for driving spikes having varying shaped heads and fully seating the heads. The tool includes a central striking member adapted to be reciprocably engaged in and driven by the power hammer. The striking member is encircled by a free floating casing adapted to fit over the spike head for proper guidance of the same, the casing having predetermined clearance to accommodate reciprocation of the fast moving striking member. The casing may be spring loaded. Means for easy assembly and disassembly are provided.

United States Patent [191 Larson Aug. 6, 1974 FLOATING TYPE DRIVE SPIKE ACCESSORY John O. Larson, Minneapolis, Minn.

Lewis Bolt & Nut Company, Minneapolis, Minn.

Filed: Dec. 8, 1972 Appl. No.: 313,453

Inventor:

Assignee:

U.S. Cl 173/128, 173/133, 403/166, 403/360 Int. Cl. B251: 3/00 Field 01 Search 173/128, 133; 145/30 R, 145/52, 30 5; 30/1646, 168, 277; 403/166, 378, 379, 360

References Cited UNITED STATES PATENTS 8/1943 Allen 173/133 5/1965 Taylor 12/1967 Cunningham 173/11 FOREIGN PATENTS OR APPLICATIONS 68,806 1943 Norway 173/133 Primary Examiner-Frank L. Abbott Assistant Examiner-William F. Pate, 111

[57] ABSTRACT A tool or accessory for use in conjunction with paving breakers or similar power hammers for driving spikes having varying shaped heads and fully seating the heads. The tool includes a central striking member adapted to be reciprocably engaged in and driven by the power hammer. The striking member is encircled by a free floating casing adapted to fit over the spike head for proper guidance of the same, the casing having predetermined clearance to accommodate reciprocation of the fast moving striking member. The casing may be spring loaded. Means for easy assembly and disassembly are provided.

14 Claims, 8 Drawing Figures FLOATING TYPE DRIVE SPIKE ACCESSORY This invention relates to a tool or accessory for use in conjunction with a power hammer such as an airdriven paving breaker or similar pneumatic hammer for driving heavy spikes having varying shaped heads and for fully seating the same.

The principal object of the present invention is to provide a free floating casing surrounding the striking member, said casing being adapted to fit over the spike head for proper guidance of the spike while being driven.

A further object of the invention is to provide a spring-loaded thrust against said guiding casing whereby the casing is driven with reduced force required to seat the thinner edge portions of certain dome head spikes so as to prevent the tendency of those edges to curl up and be susceptible to being caught by snow plow blades and similar highway equipment.

Another object of the invention is to provide complementary mating collar means for securing spring-biased spike guidance casings to the striking member.

Other objects of the invention will become apparent as the description proceeds.

To the accomplishment of the foregoing and related ends, this invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative however, of but a few of the various ways in which the principles of the invention may be employed.

The invention is illustrated in the accompanying drawings in which the same numerals refer to corresponding parts and in which:

FIG. 1 is an elevation, partly in section, showing a conventional pneumatic hammer fitted with a tool according to the present invention as used for driving railraod spikes for securing ties;

FIG. 2 is a fragmentary elevation, in section and on a larger scale, taken on the line 2-2 of FIG. 1 and in the direction of the arrows;

FIG. 3 is a fragmentary elevation, partly in section, showing a modified form of tool according to the present invention as used for driving dome head spikes;

FIG. 4 is an elevation of a further modified form of tool according to the present invention as used for driving washer head spikes;

FIG. 5 is an elevation, partly in section, taken on the line 5-5 of FIG. 4;

FIG. 6 is a horizontal section on the line 66 of FIG.

FIG. 7 is an elevation, partly in section, showing in partly exploded form portions of a locking collar used to secure the spike guidance casing on the tool for easy assembly and disassembly; and

FIG. 8 is a horizontal section on an enlarged scale taken on the line 8-8 of FIG. 7.

Referring now to the drawings, in FIG. 1 there is shown a conventional pneumatic hammer, in this instance a paving breaker, indicated generally at 10. The hammer comprises a cylinder 11 enclosing a piston 12 adapted to be energized in the conventional manner by compressed air introduced through a hose 13. The operation of the hammer is controlled through a lever 14 located in handle 15 for opening and closing a throttie valve for regulating the flow of compressed air to the piston. Piston l2 strikes ram 16 for limited reciprocal movement within cylinder 17. Typically the stroke of a pavement breaker is about 1 9/16 inch (40 mm) delivered at the rate of about 30 per second.

The pneumatic hammer 10 includes an elongated cylindrical barrel 18 of circular cross section having a socket sleeve or liner 19 of polygonal cross section, usually hexagonal, to receive the shank 20 of the spike driving tool, indicated generally at 21, to hold the same against rotation, shank 20 being of the same polygonal cross section and adapted to be held with a slide fit within socket liner sleeve 19. In order that the tool may be retained within the pneumatic hammer, it is provided intermediate of its ends with an outwardly extending annular flange 22. Flange 22 may be formed by forging or may be a sweated collar but preferably is in the form of a collar fitted around the outside of the tool and secured by means of a pin 23. Flange or collar 22 is held with a slide fit within barrel l8 and locks therein by means of a pawl-like retaining lever 24 pivotally mounted in one side of the barrel housing at 25 and held in locking position by means of a spring-biased plunger 26.

The opposite end of tool 21 includes a cylindrical body 27 of circular cross section having an enlarged striking head 28, the juncture between the body and striking head providing a tapered shoulder 29. A belllike guide casing, indicated generally at 30, surrounds the tool body 27 and encompasses the striking head 28. Casing 30, as best seen in FIG. 2, comprises a tubular shank 31 adapted to be held with a slide fit in movable engagement with too] body 27 and a head 32 adapted to similarly engage the tool striking head 28.

The striking face 33 of tool head 28 is concave or dished with a radius of curvature approximating the convex radius of curvature of a spike to be driven. The end of casing head 32 is provided with a recessed annular shoulder 34 which desirably has a radius of curvature equal to that of striking face 33 such that when casing 30 is at rest against tool shoulder 29, concave face 33 and annular shoulder 34 together form a unitary concave recess of depth approximately equal to the thickness of the spike head. The perimeter of the casing head surrounding that recess provides an annular skirt 35. Casing 30 is free floating in the sense that it is free to move reciprocably relative to the tool body and head and is free to rotate.

Spikes such as driven by a tool such as that of the present invention ordinarily are placed in pre-drilled countersunk holes, usually in timber. The casing serves to guide the head of the spike in its inward movement remaining in engagement with the spike head as it is driven. Because the casing is free floating, it does not interfere with full countersinking of the spike. In addition, the momentum of the casing as it is moved with the striking tool but is free to move independently of that tool delivers an additional impact. In the case of a broad head spike, this impact is delivered against the peripheral edges of the spike causing the head to lay flat, so as to minimize the possibility that the spikes may be caught by snow plow blades and similar highway maintenance equipment.

As shown in FIG. 1, the tool is in use to drive a railroad spike 36 having an offset head 37 adapted to engage the base of a rail 38 as it secures the rail and tie plate 39 to a railroad tie 40. It will be noted that the concave recess formed in the striking face and the casing engages the head 37 of the spike and the annular shoulder 34 of the casing exerts driving force against the overhanging Offset portion of the spike head. Although FIG. 2 shows the end elevationof-a railroad spike, the overall configuration is generally thesame as that of a dome head spike, illustrating the versatility of the tool.

FIG. 3 illustrates the tool in use to drive a dome head spike 41 and countersink the same in a timber member 42. The tool 21 is of generally the structure described with respect to FIGS. 1 and 2. Because the tool is used in its vertical orientation, casing 30 is maintained generally in position embracing striking head 28 by gravity. Where the tool is used for driving certain broad headed dome and washer head spikes, helical spring means 45 are desirably provided in order to urge the floating casing into at-rest engagement with the striking head of the tool and to impart striking blows to the perimeter of the spike head to insure that it lies flat. One end of spring 45 surrounds casing shank 31 and seats against such that, as seen in FIGS. 6 and 8, the split collar fits in engagement with body 27 between ring 48 and the end of enlarged body section 50 and is held in place there by virtue of spring retainer collar 46 passing in casing head 32. The opposite end of the spring sur- 7 rounds a spring retaining collar 46 provided with an outwardly extending annular flange 47 against which the end of the spring seats. Collar 46 is held in slidable engagement with tool body 27 by means of a retainer ring 48, of structure corresponding generally to that of collar 22 already described, and spaced therefrom. Tension on spring 45 can be predetermined by the location of collar 48.

. The tool of FIGS. through 8 is generally similar to that of FIG. 3 except that means are provided for easy assembly and disassembly of the striking member, casing, spring and spring retaining means, etc. for repair or replacement of parts. This modified form of structure is shown in use in conjunction with a washer head spike 49.

The modified form of tool, indicated generally at 21A, has a non-circular shank and circular collar 21 as heretofore described. The cylindrical body 27 is of approximately the same diameter as the maximum dimension of the polygonal cross section of shank 20. The end 50 of tool body 27 adjacent the striking head 28A is of greater diameter approximately equal to the diameter of collars 22 and 48. This necessitates casing 30A being of correspondingly larger diameter along with spring 45A and spring retaining collar 46A, all of which are adapted to be moved for disassembly by passing toward the shank over rings 22 and 48. As previously described, one end of spring 45A surrounds the shank 31A of casing 30A and seats against the head 32A and the opposite end of the spring surrounds collar 46A and seats against flange 47A.

The spring retaining collar 46A is held in place by means of a split locking collar composed of segments 51 and 52 each having an outwardly extending flange portion 53 and 54, respectively. The inside diameter of the collar composed of segments 51 and 52 is of a dimension adapted to engage the cylindrical surface of tool body 27 with a slide fit. The outside diameter of that split collar is of a dimension to engage the inside perimeter of retainer collar 46A with a slide fit and the outside diameter of the split collar flange composed of segments 53 and 54 is greater than the inside diameter of collar 46A. The inside end of the enlarged portion 50 of tool body 27 is spaced from collar 48 by approximately the length of the segments of split collar 51-52 sliding engagement over the outer perimeter of the split collar under. force of spring A.

To disassemble the casing 30A from the tool, spring 45A is compressed by forcing collar 46A toward the casing sufficient distance to free the split ring segments 51 and 52 to permit them to be disengaged from the tool by moving laterally. Then, upon relaxation of spring 45A, by virtue of the diameters of collar 46A, spring 45A and casing 30A all being slightly greater than the diameter of rings 22 and 48, collar 46A, spring 45A and casing 30A can all be passed over collars 22 and 48 over shank 20 and disengaged from the tool. When the unit is reassembled, the spring is once again compressed and locked into place by slipping the split collar into engagement with tool body 27 and then relaxing the spring by permitting collar 46A to slide into surrounding engagement with the split ring.

In the embodiments of FIG. 3 and that of FIGS. 5 through 8, the casings 30 and 30A, respectively, are still free floating relative to the tool body but the degree of free reciprocal movement is determined by the tension exerted by springs 45 and 45A, respectively.

It is apparent that many modifications and variations of this invention as hereinbefore set forth may be made without departing from the spirit and scope thereof. The specific embodiments described are given by way of example only and the invention is limited only by the terms of the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A floating type drive spike accessory tool for use in conjunction with a power hammer for driving spikes of varying shaped heads, said tool comprising:

A. an elongated striking member having 1. an elongated shank of non-circular polygonal cross section at one end, and

2. an elongated cylindrical body of circular cross section at the other,

B. a projecting annular flange on said member be tween said shank and body,

C. a cylindrical striking head of enlarged diameter at the free end of the tool body,

D. a striking face at the end of said striking head,

E. a cylindrical driving casing on said body and adapted to surround said driving head and adjacent body portion in sliding engagement therewith, said casing having a recessed annular shoulder whose inner edges abut the outer edges of the striking face, and

F. a depending skirt on said casing extending beyond said sttriking face and annular shoulder when said casing is in engagement with the striking head.

2. A tool according to claim 1 further characterized in that said annular flange is a collar secured to said tool body.

3. A tool according to claim 2 further characterized in that said collar is secured by pinning.

4. A tool according to claim 1 further characterized in that:

A. said tool is provided with a further annular flange spaced from said first flange toward the striking head and disposed between said first flange and the end of said casing which is opposite from said depending skirt, and

B. a helical spring is disposed around said body compressed between said casing and said further flange.

5. A tool according to claim 4 further characterized in that a flange spring retaining collar is provided in sliding engagement with said tool body between said spring and further flange.

6. A floating type drive spike accessory tool for use in conjunction with a power hammer for driving spikes of varying shaped heads, said tool comprising:

A. an enlongated striking member having I. an elongated shank of non-circular polygonal cross section at one end, and

2. an elongated cylindrical body of circular cross section at the other,

B. a projecting annular flange on said member between said shank and body,

C. a cylindrical striking head of enlarged diameter at the free end of the tool body,

D. a striking face at the end of said striking head,

E. a cylindrical casing on said body and adapted to surround said driving head and adjacent body portion in sliding engagement therewith,

F. a depending skirt on said casing extending beyond said striking face when said casing is in engagement with the striking head,

G. a further annular flange on said member spaced from said first flange toward the striking head, a portion of said cylindrical body adjacent to the striking head being of increased diameter approximately equal to the diameters of said annular flanges,

H. a helical spring disposed around said body compressed between said casing and said further flange, said spring being of diameter to surround said enlarged body portion,

I. a flanged spring retaining collar adapted for sliding engagement with the enlarged portion of said body, and

J. a split locking collar for said spring retaining collar,

said split collar comprising:

1. a plurality of segments together forming a circular collar,

2. the inside surface of said split collar having a diameter engageable with said portion of the tool body adjacent said further flange, and

3. the outside surface of said split collar having a diameter slidably engageable with the inside surface of the spring retaining collar.

7. A floating type drive spike accessory tool for use in conjunction with a power hammer for driving the spikes of varying shaped heads, said tool comprising:

A. an elongated striking member having 1. an elongated shank of non-circular polygonal cross section at one end, and

2. an elongated cylindrical body of circular cross section at the other,

B. a projecting annular flange on said member between said shank and body,

C. a cylindrical striking head of enlarged diameter at the free end of the tool body,

D. a concave striking face at the end of said striking head,

E. a cylindrical casing on said body and adapted to surround said driving head and adjacent body portion in sliding engagement therewith, said casing being provided with a recessed annular shoulder whose inner edges abut the outer edges of the striking face, and the surface of said annular shoulder being concave with the same radius of curvature as the striking face, and

F. a depending skirt on said casing extending beyond said striking face when said casing is in engagement with the striking head.

8. A tool according to claim 6 further characterized in that:

A. said split collar segments are two in number, and

B. said segments are provided with outwardly extending flanges.

9. A tool according to claim 7 further characterized in that said annular flange is a collar secured to said tool body.

10. A tool according to claim 9 further characterized in that said collar is secured by pinning.

11. A tool according to claim 7 further characterized in that:

A. said tool is provided with a further annular flange spaced from said first flange toward the striking head, and

B. a helical spring is disposed around said body compressed between said casing and said further flange.

12. A tool according to claim 11 further characterized in that a flanged spring retaining collar is provided in sliding engagement with said tool body between said spring and further flange.

13. A tool according to claim 11 further characterized in that:

A. a portion of said cylindrical body adjacent to the striking head is of increased diameter approximately equal to the diameters of said annular flanges,

B. said spring is of diameter to surround said enlarged body portion,

C. a flnaged spring retaining collar is provided adapted for sliding engagement with the enlarged portion of said body, and

D. a split locking collar is provided for said spring retaining collar, said split collar comprising:

1. a plurality of segments together forming a circular collar,

2. the inside surface of said split collar having a diameter engageable with said portion of the tool body adjacent said further flange, and

3. the outside surface of said split collar having a diameter slidably engageable with the inside surface of the spring retaining collar.

14. A tool according to claim 13 further characterized in that:

A. said split collar segments are two in number, and

B. said segments are provided with outwardly extending flanges. 

1. A floating type drive spike accessory tool for use in conjunction with a power hammer for driving spikes of varying shaped heads, said tool comprising: A. an elongated striking member having
 1. an elongated shank of non-circular polygonal cross section at one end, and
 2. an elongated cylindrical body of circular cross section at the other, B. a projecting annular flange on said member between said shank and body, C. a cylindrical striking head of enlarged diameter at the free end of the tool body, D. a striking face at the end of said striking head, E. a cylindrical driving casing on said body and adapted to surround said driving head and adjacent body portion in sliding engagement therewith, said casing having a recessed annular shoulder whose inner edges abut the outer edges of the striking face, and F. a depending skirt on said casing extending beyond said sttriking face and annular shoulder when said casing is in engagement with the striking head.
 2. an elongated cylindrical body of circular cross section at the other, B. a projecting annular flange on said member between said shank and body, C. a cylindrical striking head of enlarged diameter at the free end of the tool body, D. a striking face at the end of said striking head, E. a cylindrical driving casing on said body and adapted to surround said driving head and adjacent body portion in sliding engagement therewith, said casing having a recessed annular shoulder whose inner edges abut the outer edges of the striking face, and F. a depending skirt on said casing extending beyond said sttriking face and annular shoulder when said casing is in engagement with the striking head.
 2. A tool according to claim 1 further characterized in that said annular flange is a collar secured to said tool body.
 2. the inside surface of said split collar having a diameter engageable with said portion of the tool body adjacent said further flange, and
 2. an elongated cylindrical body of circular cross section at the other, B. a projecting annular flange on said member between said shank and body, C. a cylindrical striking head of enlarged diameter at the free end of the tool body, D. a concave striking face at the end of said striking head, E. a cylindrical casing on said body and adapted to surround said driving head and adjacent body portion in sliding engagement therewith, said casing being provided with a recessed annular shoulder whose inner edges abut the outer edges of the striking face, and the surface of said annular shoulder being concave with the same radius of curvature as the striking face, and F. a depending skirt on said casing extending beyond said striking face when said casing is in engagement with the striking head.
 2. the inside surface of said split collar having a diameter engageable with said portion of the tool body adjacent said further flange, and
 2. an elongated cylindrical body of circular cross section at the other, B. a projecting annular flange on said member between said shank and body, C. a cylindrical striking head of enlarged diameter at the free end of the tool body, D. a striking face at the end of said striking head, E. a cylindrical casing on said body and adapted to surround said driving head and adjacent body portion in sliding engagement therewith, F. a depending skirt on said casing extending beyond said striking face when said casing is in engagement with the striking head, G. a further annular flange on said member spaced from said first flange toward tHe striking head, a portion of said cylindrical body adjacent to the striking head being of increased diameter approximately equal to the diameters of said annular flanges, H. a helical spring disposed around said body compressed between said casing and said further flange, said spring being of diameter to surround said enlarged body portion, I. a flanged spring retaining collar adapted for sliding engagement with the enlarged portion of said body, and J. a split locking collar for said spring retaining collar, said split collar comprising:
 3. the outside surface of said split collar having a diameter slidably engageable with the inside surface of the spring retaining collar.
 3. A tool according to claim 2 further characterized in that said collar is secured by pinning.
 3. the outside surface of said split collar having a diameter slidably engageable with the inside surface of the spring retaining collar.
 4. A tool according to claim 1 further characterized in that: A. said tool is provided with a further annular flange spaced from said first flange toward the striking head and disposed between said first flange and the end of said casing which is opposite from said depending skirt, and B. a helical spring is disposed around said body compressed between said casing and said further flange.
 5. A tool according to claim 4 further characterized in that a flange spring retaining collar is provided in sliding engagement with said tool body between said spring and further flange.
 6. A floating type drive spike accessory tool for use in conjunction with a power hammer for driving spikes of varying shaped heads, said tool comprising: A. an enlongated striking member having
 7. A floating type drive spike accessory tool for use in conjunction with a power hammer for driving the spikes of varying shaped heads, said tool comprising: A. an elongated striking member having
 8. A tool according to claim 6 further characterized in that: A. said split collar segments are two in number, and B. said segments are provided with outwardly extending flanges.
 9. A tool according to claim 7 further characterized in that said annular flange is a collar secured to said tool body.
 10. A tool according to claim 9 further characterized in that said collar is secured by pinning.
 11. A tool according to claim 7 further characterized in that: A. said tool is provided with a further annular flange spaced from said first flange toward the striking head, and B. a helical spring is disposed around said body compressed between said casing and said further flange.
 12. A tool according to claim 11 further characterized in that a flanged spring retaining collar is provided in sliding engagement with said tool body between said spring and further flange.
 13. A tool according to claim 11 further characterized in that: A. a portion of said cylindrical body adjacent to the striking head is of increased diameter approximately equal to the diameters of said annular flanges, B. said spring is of diameter to surround said enlarged body portion, C. a flnaged spring retaining collar is provided adapted for sliding engagement with the enlarged portion of said body, and D. a split locking collar is provided for said spring retaining collar, said split collar comprising:
 14. A tool according to claim 13 further characterized in that: A. said split collar segments are two in number, and B. said segments are provided with outwardly extending flanges. 